In recent years, use of directed self-assembly (DSA) has received attention as a fine patterning technique. In a pattern formation method using DSA, a self-assembly material such as a block copolymer (BCP) is applied onto a guide pattern and microphase-separated to form a microphase separation pattern along the guide pattern.
In the pattern formation method, it is important to observe a progress degree of phase separation of a self-assembly material for setting conditions for a phase separation process.